Looking to buy an iPhone 4S in person on Friday after reading some of the glowing reviews it has racked up? Your instinct might be to show up extra-early at your local Apple Store, but other strategies could save you some time.

Apple says that the iPhone 4S will be available on a first-come, first-served basis in its stores on Friday. Apple's retail stores will open at 8 a.m., as will the carrier stores for AT&T, Sprint, and Verizon. However, not all of the companies involved--including Apple--promise that iPhones will available for everyone who wants one.

Representatives emphasize that quantities are limited at each store, so we recommend calling ahead to see whether you have a chance of getting your hands on an iPhone if you simply show up and walk in.

Call Ahead

"We're really hoping for a lot. It's going to be fun," says a representative of the Apple Store branch in Palo Alto, California. He suggests that customers call in on Thursday night to gauge the likely wait.

"Seeing how things are the night before will give you a clue as to how crazy it will be the next day. In launches in the past, we've had people wait 12 whole hours before our store opened," the rep notes.

If you're hoping to avoid the crowds, your best bet might be to visit one of your carrier's outlets and not an Apple Store. But there are no guarantees.

According to a company representative in Marin, California, Verizon anticipates a lot of traffic. "We're expecting a big rush and a big line--people might be camping out for a phone," he says, adding that it may be more convenient for customers to preorder a phone, as supplies will be limited on Friday.

Meanwhile, an AT&T rep in Fremont, California, advises people to come in on Friday at 8 a.m. "If you don't get your phone on Friday, we can back-order it for you for free--meaning it will be shipped directly to you at no cost. You'll just have to wait a little longer." A little longer is 14 to 21 days. But hey, the shipping is free.